نتایج جستجو برای: solar radiation ultraviolet index skinsynthesisof vitamin d radiation protection
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BACKGROUND In general, measurements of solar ultraviolet (UV) radiation are related to horizontal surfaces. While the humans walking and standing outdoors expose to the natural solar UV radiation, their eyes, cheeks, extremities, trunks, or many other anatomical sites are close to vertical plane and random orient to different directions. In this study, we characterized the diurnal variations in...
conclusions comprehensive protection programs with on-the-job training courses for staff members are strongly recommended, as well as, the provision of radiological shields and gonad shielding protocols in radiology departments to reduce the patient’s radiation dose during radiological examinations. materials and methods a retrospective, observational cross-sectional study on the application of...
Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are...
More than a century ago, ionizing radiation was observed to damage the radiosensitive small intestine. Although a large number of studies has since shown that radiation reduces rates of intestinal digestion and absorption of nutrients, no study has determined whether radiation affects mRNA expression and dietary regulation of nutrient transporters. Since radiation generates free radicals and di...
background: vitamin d, especially its most active metabolite 1,25-dihydroxyvitamin d₃(vit d) is essential in regulating a wide variety of biologic processes, such as regulating mesangial cell activation. the objective of this study was to assess the histopathological changes of effectiveness of vit d as a protective agent against radiation induced lung injury. materials and methods: eighteen wi...
Ultraviolet (UV) radiation is a carcinogen that also compromises skin appearance and function. Since the UV action spectra for DNA damage, skin cancer, and vitamin D photosynthesis are identical, and vitamin D is readily available from oral supplements, why has sun protection become controversial? First, the media and, apparently, some researchers are hungry for a new message. They have also dr...
BACKGROUND Vitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North-South making it an ideal place to study...
background: radioprotective effect of famotidine was previously shown on radiation induced micronuclei and chromosomal aberrations in human peripheral lymphocytes and mouse bone marrow cells however, its radioprotective property has never been studied in mouse spermatogenesis. it was also shown that vitamin c as an antioxidant also exert its radioprotective effect on many biological systems, bu...
Exposure to solar ultraviolet B radiation during the summer months is the main source of vitamin D (VD) for people living in northern latitudes. The aim of this study was to determine whether artificial narrowband ultraviolet B (NB-UVB) whole-body exposures could maintain VD levels in winter. The intervention group received 2 standard erythema doses (SEDs) of NB-UVB exposures every second week ...
OBJECTIVE Solar ultraviolet (UV) radiation is an important environmental factor that affects human health. The understanding of diurnal variations of UV radiation at anatomical sites may be helpful in developing ways to protect humans from the harmful effects of UV radiation. METHODS In order to characterize the diurnal variations, the UV exposure values were measured at 30 min intervals by u...
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